Alkali-free chlorine-free dormancy agent-awakening agent composition for wet shotcrete and application method thereof

Abstract

An alkali-free chlorine-free dormancy agent-awakening agent composition for wet shotcrete and an application method thereof are disclosed. The dormancy agent in the composition includes fluosilicate,hydroxy carboxylic acid, a chelating agent, polyacrylic acid and water. The awakening agent in the composition includes a water-soluble calcium salt, alkanolamine, silica sol and water. Beneficial effects of the composition are that the composition is free of potassium, sodium and other alkali metal ions, and does not contain chloride ions. The composition can effectively improve the retention time of the wet shotcrete, can effectively improve spraying effect of the wet shotcrete, and has good adaptability to alkaline and non-alkali accelerators, and the application method is simple.

Description

technical field [0001] The invention relates to the field of concrete admixtures, in particular to an alkali-free and chlorine-free dormant wake-up agent composition for wet sprayed concrete and a use method thereof. Background technique [0002] With the acceleration of traffic construction in western my country and the development of tunnel construction technology in recent years. Wet shotcrete is used in more and more tunnel primary support. After the wet sprayed concrete is mixed in the concrete mixing station, it is transported to the tunnel face for spraying construction. Since the tunnel construction is mostly located in mountainous areas with inconvenient traffic, and the working face of the tunnel construction is narrow, the delivery time of the wet shotcrete is usually 1-2 hours, or even longer. During the construction of shotcrete in tunnels, the construction interruption time is often too long due to accidents, and the mixed shotcrete cannot be unloaded due to ...

AI Technical Summary

Problems solved by technology

The addition of these substances containing alkali metal ions to concrete may cause a decrease in the strength and durability of the concrete in the later period

Studies have shown that the retarding effect of phosphonic acid organic compounds on concrete is too strong. When added to shotcrete, the adaptability to accelerators is not good, which will easily lead to poor spraying effect of shotcrete.

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